Heat the butter and oil in a large saucepan over medium-high heat until butter melts. Increase heat to high. Add onions and cook, uncovered, stirring constantly, for 5 minutes or until the onions begin to soften.

Step 2

Reduce heat to medium. Add sugar and cook, uncovered, stirring occasionally, for 30 minutes or until onions are golden and caramelised.

Step 3

Add the stock, water, wine and brandy to the pan and season well with salt and pepper. Bring to the boil over medium-low heat. Reduce heat to low and simmer, uncovered, stirring occasionally, for 15 minutes.

Step 4

Meanwhile, preheat grill on medium. Place the baguette slices under preheated grill and toast for 1-2 minutes each side or until lightly toasted. Sprinkle one side of each slice with a little of the cheese. Grill for a further 1-2 minutes or until the cheese melts and is golden.

Step 5

Ladle the hot soup into serving bowls. Top with the cheese toasts and sprinkle with pepper just before serving.

The soup will keep in an airtight container in the fridge for up to 3 days.